nfs3proc.c

《嵌入式系统设计与实例开发实验教材二源码》Linux内核移植与编译实验

/*
 * linux/fs/nfsd/nfs3proc.c
 *
 * Process version 3 NFS requests.
 *
 * Copyright (C) 1996, 1997, 1998 Olaf Kirch <[e-mail]>
 */

#include <linux/linkage.h>
#include <linux/sched.h>
#include <linux/errno.h>
#include <linux/locks.h>
#include <linux/fs.h>
#include <linux/ext2_fs.h>
#include <linux/stat.h>
#include <linux/fcntl.h>
#include <linux/net.h>
#include <linux/in.h>
#include <linux/version.h>
#include <linux/unistd.h>
#include <linux/slab.h>
#include <linux/major.h>

#include <linux/sunrpc/svc.h>
#include <linux/nfsd/nfsd.h>
#include <linux/nfsd/cache.h>
#include <linux/nfsd/xdr3.h>
#include <linux/nfs3.h>

#define NFSDDBG_FACILITY		NFSDDBG_PROC

#define RETURN_STATUS(st)	{ resp->status = (st); return (st); }

static int	nfs3_ftypes[] = {
	0,			/* NF3NON */
	S_IFREG,		/* NF3REG */
	S_IFDIR,		/* NF3DIR */
	S_IFBLK,		/* NF3BLK */
	S_IFCHR,		/* NF3CHR */
	S_IFLNK,		/* NF3LNK */
	S_IFSOCK,		/* NF3SOCK */
	S_IFIFO,		/* NF3FIFO */
};

/*
 * Reserve room in the send buffer
 */
static void
svcbuf_reserve(struct svc_buf *buf, u32 **ptr, int *len, int nr)
{
	*ptr = buf->buf + nr;
	*len = buf->buflen - buf->len - nr;
}

/*
 * NULL call.
 */
static int
nfsd3_proc_null(struct svc_rqst *rqstp, void *argp, void *resp)
{
	return nfs_ok;
}

/*
 * Get a file's attributes
 */
static int
nfsd3_proc_getattr(struct svc_rqst *rqstp, struct nfsd_fhandle  *argp,
					   struct nfsd3_attrstat *resp)
{
	int	nfserr;

	dprintk("nfsd: GETATTR(3)  %s\n",
				SVCFH_fmt(&argp->fh));

	fh_copy(&resp->fh, &argp->fh);
	nfserr = fh_verify(rqstp, &resp->fh, 0, MAY_NOP);
	RETURN_STATUS(nfserr);
}

/*
 * Set a file's attributes
 */
static int
nfsd3_proc_setattr(struct svc_rqst *rqstp, struct nfsd3_sattrargs *argp,
					   struct nfsd3_attrstat  *resp)
{
	int	nfserr;

	dprintk("nfsd: SETATTR(3)  %s\n",
				SVCFH_fmt(&argp->fh));

	fh_copy(&resp->fh, &argp->fh);
	nfserr = nfsd_setattr(rqstp, &resp->fh, &argp->attrs,
			      argp->check_guard, argp->guardtime);
	RETURN_STATUS(nfserr);
}

/*
 * Look up a path name component
 */
static int
nfsd3_proc_lookup(struct svc_rqst *rqstp, struct nfsd3_diropargs *argp,
					  struct nfsd3_diropres  *resp)
{
	int	nfserr;

	dprintk("nfsd: LOOKUP(3)   %s %.*s\n",
				SVCFH_fmt(&argp->fh),
				argp->len,
				argp->name);

	fh_copy(&resp->dirfh, &argp->fh);
	fh_init(&resp->fh, NFS3_FHSIZE);

	nfserr = nfsd_lookup(rqstp, &resp->dirfh,
				    argp->name,
				    argp->len,
				    &resp->fh);
	RETURN_STATUS(nfserr);
}

/*
 * Check file access
 */
static int
nfsd3_proc_access(struct svc_rqst *rqstp, struct nfsd3_accessargs *argp,
					  struct nfsd3_accessres *resp)
{
	int	nfserr;

	dprintk("nfsd: ACCESS(3)   %s 0x%x\n",
				SVCFH_fmt(&argp->fh),
				argp->access);

	fh_copy(&resp->fh, &argp->fh);
	resp->access = argp->access;
	nfserr = nfsd_access(rqstp, &resp->fh, &resp->access);
	RETURN_STATUS(nfserr);
}

/*
 * Read a symlink.
 */
static int
nfsd3_proc_readlink(struct svc_rqst *rqstp, struct nfsd_fhandle     *argp,
					   struct nfsd3_readlinkres *resp)
{
	u32		*path;
	int		dummy, nfserr;

	dprintk("nfsd: READLINK(3) %s\n", SVCFH_fmt(&argp->fh));

	/* Reserve room for status, post_op_attr, and path length */
	svcbuf_reserve(&rqstp->rq_resbuf, &path, &dummy,
				1 + NFS3_POST_OP_ATTR_WORDS + 1);

	/* Read the symlink. */
	fh_copy(&resp->fh, &argp->fh);
	resp->len = NFS3_MAXPATHLEN;
	nfserr = nfsd_readlink(rqstp, &resp->fh, (char *) path, &resp->len);
	RETURN_STATUS(nfserr);
}

/*
 * Read a portion of a file.
 */
static int
nfsd3_proc_read(struct svc_rqst *rqstp, struct nfsd3_readargs *argp,
				        struct nfsd3_readres  *resp)
{
	u32 *	buffer;
	int	nfserr, avail;

	dprintk("nfsd: READ(3) %s %lu bytes at %lu\n",
				SVCFH_fmt(&argp->fh),
				(unsigned long) argp->count,
				(unsigned long) argp->offset);

	/* Obtain buffer pointer for payload.
	 * 1 (status) + 22 (post_op_attr) + 1 (count) + 1 (eof)
	 * + 1 (xdr opaque byte count) = 26
	 */
	svcbuf_reserve(&rqstp->rq_resbuf, &buffer, &avail,
			1 + NFS3_POST_OP_ATTR_WORDS + 3);

	resp->count = argp->count;
	if ((avail << 2) < resp->count)
		resp->count = avail << 2;

	fh_copy(&resp->fh, &argp->fh);
	nfserr = nfsd_read(rqstp, &resp->fh,
				  argp->offset,
				  (char *) buffer,
				  &resp->count);
	if (nfserr == 0) {
		struct inode	*inode = resp->fh.fh_dentry->d_inode;

		resp->eof = (argp->offset + resp->count) >= inode->i_size;
	}

	RETURN_STATUS(nfserr);
}

/*
 * Write data to a file
 */
static int
nfsd3_proc_write(struct svc_rqst *rqstp, struct nfsd3_writeargs *argp,
					 struct nfsd3_writeres  *resp)
{
	int	nfserr;

	dprintk("nfsd: WRITE(3)    %s %d bytes at %ld%s\n",
				SVCFH_fmt(&argp->fh),
				argp->len,
				(unsigned long) argp->offset,
				argp->stable? " stable" : "");

	fh_copy(&resp->fh, &argp->fh);
	resp->committed = argp->stable;
	nfserr = nfsd_write(rqstp, &resp->fh,
				   argp->offset,
				   argp->data,
				   argp->len,
				   &resp->committed);
	resp->count = argp->count;
	RETURN_STATUS(nfserr);
}

/*
 * With NFSv3, CREATE processing is a lot easier than with NFSv2.
 * At least in theory; we'll see how it fares in practice when the
 * first reports about SunOS compatibility problems start to pour in...
 */
static int
nfsd3_proc_create(struct svc_rqst *rqstp, struct nfsd3_createargs *argp,
					  struct nfsd3_diropres   *resp)
{
	svc_fh		*dirfhp, *newfhp = NULL;
	struct iattr	*attr;
	u32		nfserr;

	dprintk("nfsd: CREATE(3)   %s %.*s\n",
				SVCFH_fmt(&argp->fh),
				argp->len,
				argp->name);

	dirfhp = fh_copy(&resp->dirfh, &argp->fh);
	newfhp = fh_init(&resp->fh, NFS3_FHSIZE);
	attr   = &argp->attrs;

	/* Get the directory inode */
	nfserr = fh_verify(rqstp, dirfhp, S_IFDIR, MAY_CREATE);
	if (nfserr)
		RETURN_STATUS(nfserr);

	/* Unfudge the mode bits */
	attr->ia_mode &= ~S_IFMT;
	if (!(attr->ia_valid & ATTR_MODE)) { 
		attr->ia_valid |= ATTR_MODE;
		attr->ia_mode = S_IFREG;
	} else {
		attr->ia_mode = (attr->ia_mode & ~S_IFMT) | S_IFREG;
	}

	/* Now create the file and set attributes */
	nfserr = nfsd_create_v3(rqstp, dirfhp, argp->name, argp->len,
				attr, newfhp,
				argp->createmode, argp->verf);

	RETURN_STATUS(nfserr);
}

/*
 * Make directory. This operation is not idempotent.
 */
static int
nfsd3_proc_mkdir(struct svc_rqst *rqstp, struct nfsd3_createargs *argp,
					 struct nfsd3_diropres   *resp)
{
	int	nfserr;

	dprintk("nfsd: MKDIR(3)    %s %.*s\n",
				SVCFH_fmt(&argp->fh),
				argp->len,
				argp->name);

	argp->attrs.ia_valid &= ~ATTR_SIZE;
	fh_copy(&resp->dirfh, &argp->fh);
	fh_init(&resp->fh, NFS3_FHSIZE);
	nfserr = nfsd_create(rqstp, &resp->dirfh, argp->name, argp->len,
				    &argp->attrs, S_IFDIR, 0, &resp->fh);

	RETURN_STATUS(nfserr);
}

static int
nfsd3_proc_symlink(struct svc_rqst *rqstp, struct nfsd3_symlinkargs *argp,
					   struct nfsd3_diropres    *resp)
{
	int	nfserr;

	dprintk("nfsd: SYMLINK(3)  %s %.*s -> %.*s\n",
				SVCFH_fmt(&argp->ffh),
				argp->flen, argp->fname,
				argp->tlen, argp->tname);

	fh_copy(&resp->dirfh, &argp->ffh);
	fh_init(&resp->fh, NFS3_FHSIZE);
	nfserr = nfsd_symlink(rqstp, &resp->dirfh, argp->fname, argp->flen,
						   argp->tname, argp->tlen,
						   &resp->fh, &argp->attrs);
	RETURN_STATUS(nfserr);
}

/*
 * Make socket/fifo/device.
 */
static int
nfsd3_proc_mknod(struct svc_rqst *rqstp, struct nfsd3_mknodargs *argp,
					 struct nfsd3_diropres  *resp)
{
	int	nfserr, type;
	dev_t	rdev = 0;

	dprintk("nfsd: MKNOD(3)    %s %.*s\n",
				SVCFH_fmt(&argp->fh),
				argp->len,
				argp->name);

	fh_copy(&resp->dirfh, &argp->fh);
	fh_init(&resp->fh, NFS3_FHSIZE);

	if (argp->ftype == 0 || argp->ftype >= NF3BAD)
		RETURN_STATUS(nfserr_inval);
	if (argp->ftype == NF3CHR || argp->ftype == NF3BLK) {
		if ((argp->ftype == NF3CHR && argp->major >= MAX_CHRDEV)
		    || (argp->ftype == NF3BLK && argp->major >= MAX_BLKDEV)
		    || argp->minor > 0xFF)
			RETURN_STATUS(nfserr_inval);
		rdev = ((argp->major) << 8) | (argp->minor);